So I see the Neogaf thread is already full of people saying this will never be localized, so I'm just going to come out and say that I think it actually has a very good shot.
First of all, VC1 actually did reasonably well in the US (though its sales started out pretty weak because there was zero hype or advertising for the game when it first came out, it ended up having a very long tail from word-of-mouth and positive feedback). On the other hand VC2 really did flop which is why we never got VC3. But on the gripping hand that has been mostly attributed to the fact that it was on the PSP, and that's probably reasonably accurate (though a lot of people were put off by the shift in tone too).
Now the PS4 has been doing great in the west and there's a vocal fanbase that has been clamoring for the third game for a while now. It seems like the perfect opportunity for a western release. In fact it actually doesn't make a lot of sense that they would do a PS4 port at this point if they weren't thinking of the west at all, because the PS4 is still kind of limping along in Japan (probably in no small part due to the lack of Japanese games for it...).
Then there's also the Atlus connection now that Sega owns them. I'm sure they would be perfectly happy to do the localizing for a game like this...
Anyway, I might actually have to get a PS4...kind of funny when I think about it. The original Valkyria Chronicles is the game I bought my PS3 for.